[Diagnosis and treatment of anorectal malignant melanoma--a report of 22 cases with literature review]

Abstract

Background & objective: Anorectal malignant melanoma (AMM) is an aggressive malignant tumor, and its treatment still remains controversial. This study was to summarize our experience on diagnosis and treatment of AMM.

Methods: Clinicopathologic records, including clinical feature, diagnosis, operation patterns, and prognosis, of 22 patients with AMM, treated in Jiangsu Provincial Cancer Hospital from 1977 to 2003, were analyzed retrospectively with literature review.

Results: The 22 patients with AMM accounted for 0.04% of all the patients diagnosed as malignant tumors of large bowel simultaneously in our hospital. Of the 22 patients, 6 were men, and 16 were women, with the median age of 61 (ranged 37-72). The most common complaints of AMM patients were hematochezia (86%), anus pain or discomfort (59%), local mass (27%), and so on. The misdiagnosis rate was 86%. The definite pathologic diagnosis rate before surgery was 48%. Of the 22 patients, 6 had distant metastasis; 11 underwent abdominoperineal resection, 5 underwent wide local excision (2 underwent salvage abdominoperineal resection who suffered from local recurrence after wide local excision), 2 underwent Parkos procedure, 1 underwent Hartmannos procedure, and 3 underwent sigmoid colostomy. The 1-, 3-, and 5-year survival rates of the 22 patients were 45.4%, 18.1%, and 9.1%, respectively. The median survival time was 12 months (95% confidence interval: 6-18 months).

Conclusions: AMM is a rare disease with poor prognosis. It tends to be misdiagnosed. Abdominoperineal resection may be considered as the first choice for the AMM patients without distant metastasis.